The present invention relates generally to label applicator apparatus. More particularly the invention relates to apparatus for applying to a surface self-adhesive labels of the type provided on an elongate backing web.
Various label applicators are known in the art for applying this type of label but each has its own problems. One significant problem which fails to be adequately addressed by known applicators is their inability to apply a single label to a surface.
Some known label applicators use mechanical indexing systems that pierce the backing web or engage registration holes manufactured into the web to feed a predetermined length of the web upon manual actuation of a trigger or the like. However, these applicators can only be used with labels of a predefined type or predefined length or range of lengths.
Other known label applicators rely on the operator to watch for the end of the label as it is being applied and to disengage the feed mechanism (by tilting the applicator for example) to prevent the next label on the web from being dispensed. These label applicators require a degree of skill on the part of the operator.
In both of these general types of known label applicators an external action or intervention is required to dispense and apply a single label to a surface. Industrial or high speed repetitive operation of such label applicators is therefore limited.
The present invention is directed to providing a label applicator which can dispense and apply to a surface a single self-adhesive label of indefinite length. It is also desirable for the label applicator to achieve this without external intervention, other than interaction between the applicator and the surface to which the label is to be applied.
The term xe2x80x9cself-adhesive labelxe2x80x9d as used throughout the specification denotes a sheet of paper or other material having a layer of pressure sensitive adhesive applied to at least a part of its surface. One surface of the sheet may display image and/or text matter. Examples of such self-adhesive labels include product packaging labels, address labels, postage stamps, price stickers, etc.
According to one aspect of the present invention there is provided apparatus for applying a self-adhesive label to a surface which is movable relative to said apparatus, said label being carried on an elongate backing web having a plurality of labels adhered to one side thereof in longitudinally spaced relationship, said apparatus including:
an edge over which said web is drawn whereby, when a force is applied along said web which exceeds a peeling threshold, said web is peeled away from said label and said label is dispensed at said edge;
pressing means located a set distance from said edge for pressing said label against said surface as it is dispensed, thereby adhering said label to said surface; and
means for applying a peeling force which is greater than said peeling threshold during dispensing of at least an initial portion of said label which spans said set distance to initiate dispensing of said label, said peeling force being operative during dispensing of said initial portion of said label and being inoperative during dispensing of a final portion of said label,
wherein when said peeling force is inoperative, dispensing is continued due to an additional force being exerted along said web by a portion of said label which is adhered to said surface.
The peeling force may be a single force applied to the web or it may be a combination of several forces acting together. In either case, the resultant force on the web should be at least sufficient to exceed the peeling threshold to initiate dispensing of the label.
Preferably a means for applying a take-up force, which is below the peeling threshold, is provided during at least a part of the dispensing cycle for taking up the peeled backing web from the edge. The means for applying the peeling force may include the means for applying the take-up force. The take-up force may also form part of the peeling force.
According to a further aspect of the present invention there is provided apparatus for applying a self-adhesive label to a surface which is movable relative to said apparatus, said label being carried on an elongate backing web having a plurality of labels adhered to one side thereof in longitudinally spaced relationship, said apparatus including:
an edge over which said web is drawn whereby, when a force is applied along said web which exceeds a peeling threshold, said web is peeled away from said label and said label is dispensed at said edge;
pressing means located a set distance from said edge for pressing said label against said surface as it is dispensed, thereby adhering said label to said surface; and
means for applying, in a first mode, a driving force and, in a second mode, a take-up force along said backing web, said driving force being greater than said peeling threshold to initiate dispensing of said label, said driving force being operative over at least an initial portion of said label which spans said set distance and being inoperative over a final portion of said label, said take-up force being below said peeling threshold and being sufficient to take up said peeled backing web from said edge,
and wherein, during dispensing of said final portion of said label when said driving force is inoperative, movement relative to said apparatus of said surface and a portion of said label which is adhered thereto provides an additional force along said backing web, said take-up and additional forces together exceeding said peeling threshold to continue dispensing of said label.
In this embodiment the driving force and take-up force may both be applied to the peeled or waste portion of the backing web, leaving the edge at which the label is dispensed. In this way, each force may act to pull the web around the edge.
During dispensing of the final portion of the label, the additional force arising from the label itself being partially adhered to the surface may act to pull the web toward the dispensing edge. The additional force alone may be sufficient to exceed the peeling threshold or it may act in conjunction with the take-up force to exceed the peeling threshold. In either case, dispensing of the label may be continued.
According to a still further aspect of the present invention there is provided apparatus for applying a self-adhesive label to a surface which is movable relative to said apparatus, said label being carried on an elongate backing web having a plurality of labels adhered to one side thereof in longitudinally spaced relationship, said apparatus including:
an edge over which said web is drawn whereby, when a force is applied along said web which exceeds a peeling threshold, said web is peeled away from said label and said label is dispensed at said edge;
take-up means for taking up said peeled backing web from said edge, said take-up means being adapted to apply a take-up force to said web which is below said peeling threshold;
pressing means located a set distance from said edge for pressing said label against said surface as it is dispensed, thereby adhering said label to said surface; and
means for applying a supplemental force along said backing web to supplement said take-up force, said take-up and supplemental forces together exceeding said peeling threshold to initiate dispensing of said label, said supplemental force being operative over at least an initial portion of said label which spans said set distance and being inoperative over a final portion of said label,
and wherein, during dispensing of said final portion of said label when said supplemental force is inoperative, movement relative to said apparatus of said surface and a portion of said label which is adhered thereto provides an additional force along said backing web, said take-up and additional forces together exceeding said peeling threshold to continue dispensing of said label.
In this embodiment the take-up force may be present throughout a dispensing cycle and the supplemental force may be applied to initiate dispensing of the label. The take-up force may be applied to the peeled or waste portion of the backing web leaving the edge at which the label is dispensed. The take-up force may thus assist in pulling the web around the edge, but may not be sufficient by itself to dispense a label.
The supplemental force may be applied to a portion of the web approaching the dispensing edge. In one embodiment the supplemental force may be applied to a front face of the label being dispensed. In this way, the label and web may be pushed toward the dispensing edge, at least during dispensing of the initial portion of the label.
The label applicators of the invention may automatically apply a single label to the surface without external action or intervention. This is because the peeling force to overcome the peeling threshold, whether that be a single driving force or the combined action of a take-up force and a supplemental force, may be applied to the web for the initial portion of the label only and not the final portion. For the final portion, the label itself may provide the additional force on the web needed to complete the dispensing cycle. Upon completion of a dispensing cycle, when the label is fully separated from the backing web, there may no longer be sufficient force on the web to dispense the next label. The take-up force may then act on the web and that take-up force, being below the peeling threshold, may be insufficient to initiate dispensing of the next label.
A label applicator apparatus according to the present invention may be used for:
application of labels for a variety of purposes;
application of postage stamps when carried on a backing web;
application of price stickers;
application of any material that is carried on a backing web and can be removed therefrom by pulling the web around an edge, such as an edge of a peel plate.